Process of chlorinating propane and isobutane and their partially chlorinated derivatives



Feb. 14, 1939. H B. HAss ET AL 2,147,577

PROCESS OF CHLORINATING PROPANE AND ISOBUTANE AND THEIR PARTIALLYCHLORINATED DERIVATIVES Filed May 5, 1955 2 Sheets-Sheet H. B, HAss ETAL 2,147,577 PRQCESS OF CHLORINATING PROPANE AND ISOBUTANE AND Feb. M,1939.

THEIR PARTIALLY CHLORINATEDADERIVATIVES Filed May 3, 1935 2 Sheets-SheetPatented Feb. 14, 1939 amsn rnocnss or conrnn'rrnn anonima ISOBUTANE ANDTEEUR PAR YCHLO- RINATED DEATVES Henry Hass and Earl T. PficBee, WestElaayette, llnd., assigner-s to Purdue Research Foundation, WestLafayette, End., a corporation oi Indiana ippiicationliii'ay', 1935,Seriali No. 9.54@

f l 1e claims.

It is the object of our invention to synthesize 1,3-dichloropropane and1,3-dichloro-2-methylpropane by the chlorination of propane and/ori-cnloropropane, and isobutane and/or l-chloroz-'nethylpropanarespectively. This present application 4is a continuation in part of ourearlier applications Serial No. 590,046, iiied February 1, 1932, and No.723,366, led May l, 1934, now Patent Nos. 2,004,072 and 2,004,073,

respectively, both granted June 4, 1935.

While various hydrocarbons have been chlorin ated for many years, priorto our Work very vlittle ha'sbeen done'in chlorinating isobutane.Two-thirds of a century ago, in 1867, Butlerow d did indeed report (seeChemical Reviews, volume 8, p. 30, year 1931) that he chlorinated isobu=tane, by exposing a gaseous mixture of ten volumes of isobutane and ninevolumes of chlorine to the action oi daylight at room temperature; but,according to his report, 2-chloro-2-methylpropane (tertiary butylchloride) and a more highly chlorinated liquid boiling at 105V(presumably 1,2-dicl1loro-2-methylpropane) were the only productsobtained. Y

Similarly, prior to our work very little has been done in chlorinatingpropane. In that case also, there was a report of the chlorinating ofpropane about two-thirds of a century ago, when in 1869 Schorlemmerreported' that he carried out such chlorination by the action ofsunlight at room temperature on a gaseous mixture of chlorine andpropane in a bell-jar; but, according to his report, the onlydi-chloride obtained was 1,2- dichloro-propane. (See summary in ChemicalReviews, vol. 8, pages 1-80, 1931, by Eglo',

Schaad, and Lowry.)

Indeed, according to acommonly accepted rule for chlorination, (whichrule is shown by our work to be erroneous), the only dichloridesobtainable by the chlorination of propane and isobutane are1,2-dichloropropane and 1,2-dichloro- 2-methylpropane respectively; sothat according to that rule it was impossible so to obtain 1,3-dichloropropume or 1,3 -dichloro-Z-methylpropane. That commonly acceptedrule is with reference to the halogenation of alkyl halides-ior informing a dichloride of isobutane by chlorine substitution it isnecessary tojorm rst a monochioride-and is aptly summarizedv in thewords of Herzfelder (quoted on page 4 of the summary (m. 2MB- 330) inChemical Reviews, volume 8, pp. l to 80, year i931, by Egloi, Schaad,and Lowry):

When in a monohalogen compound, a second halogen .atom is introduced, italways attaches itself to that carbon atom which is situated next to thecarbon atom already united with halogen. 1

This supposedly universal rule has seemed to be supported by manyreports. Thus: Schyen, (ibid. p. 29), in chloriinating n-butane,reported only butylene dichloride as a dichlorination product, and inany butylene dichloride the two chlorine atoms are necessarily onadjacent carbcn atoms; Schlorlemmer, (Phil.v Trans. 18, 29 (1869)), inchlorinating propane reported only propylene dichloride(1,2-dichloropropane) as a dichlorination product; and Butlerow, when hechlorinated isobutane many years ago, reported only. a liquid boiling at105 C., presumably 1,2-

dichloro-2-methylpropane (iscbutylene dichloride), as a dichlorinationproduct. The Sharples Solvents Corporation (Bulletin Chemicals De-Arived from the Pentanes") lists only .l,2dichloro= pentane,2,3dichloropentane, and 2,3-dichloro- ZL-methyibutane, as dichloridesproduced in the chlorination oa mixture of n-pentane and isopentane.1in-all. these no dichlorination is re-1 sorted in which chlorine issubstituted on two non-adjacent carbon atoms of al paramn hydrocarbon.

We have obtained in the substitutive chlorination or propane andisobutane, in addition to 1,2-dich1oropropane and .1,2-dichloro-2-methylpropane respectively, a considerable amount oi other dichlorides of saidhydrocarbons; and have found that in these dichlorides the1,3-dichlorides are not only present, contrary to the commonly acceptedrule above referred to, but are the ones which usually predominate.

We have also found that by controlling the conditions We may increasethe proportion' of these 1,3-dichlorides; by carrying out thechlorination procedure wholly at high temperature, whether inVapor-phase chlorination or in liquidphase chlorination. In the lattercase the temperature advantageously closely approaches the criticaltemperature. See our aforesaid co-pending applications Serial Nos.590,046 and 723,366, now Patent'Nos. 2,004,072 and 2,004,073; and ourco-pending application Serial No. 25,632, i'iled June 8, 1935.

When propane is chlorinated, the variants in the chlorination productsup to and including dichlorides, are Yshown by the following:

(1) GHz-0 y (Propane) (0h1rins)\ enfoca-omasex (2,2-diahloroff manne)(s) oni-onoi-om-rox. 'or

(khlmprome) CHGl-,CHi-Cnicwncl (l,3dichloropropane) Thus1,2-dichloropropane lmay be formed by the chlorination of either1-'ch1oropropane or 2- chloropropane. f When isobutane is chlorinated,lthe variants ih the chlorination products, upto and includf ingdichlorides, are shown by the following:

Therefore. we prefer to operate under conditions vwhich raise theproportion of chlorination of the primary carbon atoms,f'as by thermalchlorinaltion at relatively high temperatures. in either liquid or vaporphase, to obtain maximum yields, nrst; of primary monochlorides, andsecond of the desired 1,3-dichlorides; the optimum temperature beinghigher in vapor-phase chlorination than in liquid-phase chlorination.However, we have obtained substantial amounts of 1,3-dichlorides even atas low as 65 C., which is not only far below the critical temperaturebut far bechlorides obtained may low the"boiling point at normalpressure; so that our process includes not only chlorination underoptimum conditions for primary-carbon chlorination, as thermalchlorination, whether in vapor-phase or liquid-phase, but also, eitherwith or without thermal acceleration, a chlorination of propane orisobutane and/or their primary monochlorldes under other conditions.Either photochemical or catalytic acceleration gives good results.

-In thermal chlorination at relatively high temperatures, especially invapor-phase chlorination, we prefer to heat both the chlorine and thehydrocarbon or monochloride separately to the desired reactiontemperature, and to mix 'them at that temperature; for which purpose itis desirable, in orderto prevent flame, that one of the iluids beinjected into the other at a high lvelocity. so that it entersjn excessof the speed of flame propagation, and to have such injection with aturbulent :tiowv which produces an intimate fmixing which enables theingredients to become uniformly dispersed in each 'other before anyconsiderable amount of chlorination takes place; for this avoids theformation ofundu'e amounts of highly chlorinated products, which areformed if the reaction occurs in the presence of a local excess ofchlorine.

In the chlorination process, both polychlorinated products ancllmonochlorinated products are obtained. Byproviding suiilcient chlorine,

at one or more jets, and re-cycling the monochlorides, the proportion ofdiclilorides to monobaincreasea In any ofthese cases, the chlorinationof propane or isobutane yields chlorides other than the desired1,3.-dichloride. 'I'hese other chlorides, whether monochlorides orpolychlorides, are desirably suitably separated fromy the desired1,3-dichloride, conveniently by rectification. That can readily be done,on account of the fairly wide diiferences in the boiling points'involved.

We may separate the primary monochloride from the 2chloro derivativeobtained )according to equations 1 and 4, and alsofrom any polychlorideswhich are. produced at the same time; then recycle the primarymonochloride to chlorinate it in accordance with equation 3 or65desirably under conditions which yield a'maximum amountof the1,3-dich1oride; and then separate` the 1,3j-dichloride from otherchlorides present. 'I'he essential features of our process are thesubstitutive chlorination of either the hydrocarbon (propane orisobutane) or its primary monochloride, or both, to yield the1,3-dichloride; and

the separation of that 1,3-dichloride from other chlorides present. i

We may carry out our process with various forms of apparatus. Onesuitable form for vapor-phase chlorination is essentially that of *ourco-pending application Serial No. 590,046, now Patent No.12,004,072, orthat of our co-pending application Serial No. '723.366, nowPatent No.2,004,073. One suitable form for liquid-phase chlorination isessentially that of our co-pend- Sing application .Serial No. 25,632,filed June 8. 1935. The accompanyingv drawings show those apparatuses,with some variation.

In those drawings: Fig. 1 is a diagrammatic view of an apparatus forvapor-phase chlorination; Fig. 2 isa fragmental diagrammatic viewshowing a modiiication oi' part of that apparatus; Fig. 3 is anotherfragmental diagrammatic view, showing another modiication; and Fig. 4

is a diagrammatic view, also fragmental, oi' an -apparatus forliquid-phase'chlorination.

rinated is supplied by a/valved pipe l@ and the.

, chlorine by a valved pipe li. The hydrocarbon Sii may, ii desired, bediluted by an inert diluent, such as nitrogen, supplied by/a pipe d; butif so the diluent does not enter into the chemical reaction, although itdoes e'xert an eect on physical conditions, as by its capacity to'absorb heat. This diluent is often desirable in the chlorination oipropane or isobutane; but is especially desirable to get a quick heatingof the material to be chlorinated if such material consists wholly ofthe primary monochloride, in which case .the

nitrogen supplied may be hot. l

The proportions ci the hydrocarbon and the chlorine are desirablycontrolled to keep the chlorine present below that necessary for anexplosive mixture.

The hydrocarbon-supply pipe l@ and the chic-1 rino-supply pipe ilpreferably lead to 'separate vaporizing and/or preheating coils l2 andirespectively, located in a suitable heating device ifi; which isconveniently an ordinary bath of water or of molten salts according tothe temperature desired. Ordinarily the hydrocarbon and chlorinesupplied are in liquid iorm,'so that vaporlzation is necessary to getthem-aiuto the.

gaseous phase in which we conduct our process in this apparatus; anddesirably we preheat both the hydrocarbonv and the chlorine additionallyin the coils i2 and i3, to raise them to a desired reaction temperaturebefore mixing them. This is desirable to obtain a maximum proportion oiprimary monochlorlde in the monochlorides formed, and oi l-dichloride inthe dichlorides/ formed; and to obtain these maximum proportions inthermal chlorination the temperature to which the gases are raisedbefore being mixed should be at least 259 C., and desirably should be inthe neighborhood of about 509 C. but not over 603 C. These desiredtemperatures are usually lower than that in photochemical and incatalytic chlorination, as well as in liquidphase chlorination.

The hydrocarbon 4(propane or isobutane) and the chlorine, either or bothtreated if desired, desirably pass separately as gases to a reactionpassage it, where they are mixed at high velocity and react. Thevelocity of injection of one gas into the other, as has already beenstated, should be. greater than the speed of dame propagation oi thechlorination reaction, and is usually of the order of iifty to a hundredmiles per minute.

The chlorine supplied is under suicient pressure to produce this speed.The reaction tube la is desirably a crooked one, as is shown in Figs. 1and 3, to create a turbulence which produces intimate diffusion 'of thehydrocarbon and the chlorine in each other before any considerablechlorination has occurred, so that iame is effectively prevented and theformation of free carbon lessened and practically avoided. However,especially in photoohemical or catalytic chlorination, the reactionpassage may be in the form of a straight tube ide, as is shown in Fig.2. The chlorine is injected into the reaction tube l@ or lila by one ormore jets i5. A single jet is shown in Figs. l and 2, and a plurality ofjets lb in Fig. 3. When there are a. plurality of such jets li, they aredesirably` arranged at spaced points along the crooked reaction tube le,as is clear from Fig. 3, so that the reaction of the chlorine injectedat one jet may be completed or nearly so before the chlorine from thenext Jet is introduced. `'I'he reaction passage, especially if itis acrooked one as is the reaction passage it in Figs. 1 and 3, is desirablyimmersed in a bath il, as of molten salts, to obsorb the heat of thereaction, which is an exothermic one; although if the chlorination is4photochemical or catalytic, such bath il may be omitted, as in Fig. 2.Suitable burners I 8 may be provided for heating the bath containing thecoils l2 and it,

and for initially heating the heat-absorbing- When the chlorination isto be a photochemical chlorination, suitable light-giving devices, suchas incandescent bulbs id, may be provided around the,i reaction tubeite; if the reaction tube is made of some material, such as silica orglass, which permits the passage through its walls of thereaction-accelerating light. When the chlorination is to be catalytic,any suitable catalyst 2li may be put in the reaction tube IEB. Bothphotochemical and catalytic acceleration may be used, asis shown in Fig.2. Various catalysts may be used: such as granular carbon, cupricchloride, nickel chloride, or other known chlorination catalysts; aswell as olelnes, the

may be used, such as heat and light, r heat and a catalyst, or light anda catalyst, or lightand heat and) a catalyst. In general, the temperaeture of the reaction may be lowered if a catalyst or light is used toaccelerate the reaction.

The reaction products, with any recycled unreacted hydrocarbon (propaneor isobutane), for desirably there is an excess of hydrocarbon so thatthe formation of trichlorides and more highly chlorinated products isminimized, pass from the reaction tube it or l5@ immediately to the worm2l or" a cooler 22; by which they are cooled quickly to a temperatureinthe neighborhood of room temperature. This immediate' cooling lessenspyrolysis.

From the worm 2i, the reaction products pass to a rectifying column 23,oi any suitable type.

The temperatures in this rectifying column 23 are so controlled that thechlorinated hydrocarbons or mixed chlorides pass as liquid to the bottomoi the column whence they may be drawn q through a pipe 2d.

The remaining mixture oi hydrogen chloride and unreacted hydrocarbon,together with the inert diluent (such as nitrogen) if any is present,pass out at the top of the rectifying column 2d, and is divided inconventionall manner by a dephlegmator 2li and a'. wier-box 26 intoreflux and take-oh portions, which pass respectively by a valved refluxpipe 2l to the rectifying column 28 and into a valved take-ofi pipe 2d.The ratio between reflux and takeoff may be controlled byv cycling pumpback to the hydrocarbon-supply To this end, they may be passed throughany desired number of rectifying columns 45, 48, 41, 40,

etc., to get any desired separation.

Conveniently the first separation, in column 45. .will be betweenmonochlorides and polychlorides'.

`The monochlorides pass out at the top, and the polychlorides at the.bottom. If 'desired, the mixed monochlorides, without furtherseparation, may pass through a valved pipe 50 to a recycling pipe 5|,provided with a recycling pump 52, for returning the mixed monochloridesto any convenient point in the hydrocarbon-vaporizing-andheating tubel2; in which the recycled monochlorides are quickly heated, usually toat least 250 C., before they reach the jet I5 at which the mixing withchlorine takes place.

In some cases, however, the mixed monochlorides from the top of the/rectifying column 45 are led to the rectifying column 46, whichseparates the two monochlorides. The lower-boiling monochloride,2-chlcropropane (B. P. 35 C.) or 2- chloro-2-methylpropane (B. P. 51.5C.), passes out fromthe top' of the column 46; and may be collected in areceptacle 53. 'I'he primary monochloride, lchloropropane (B, P. 46 C.)or 1- chloro-2-methylpropane (B. P. 69 C.) passes out from the bottom ofthe rectifying column 46, by a valved pipe 54, which leads to therecycling pipe 5|. By closing the valve in the pipe 50 and opening thevalve in the pipe 54, the recycling may be of the primary monochlorideonly, without contamination by vthe monochloride which can yield none ofthe desired 1,3-dichloride.

It is usually desirable to have a preheating device 63 in the pipe5|,i'or vaporizing and producing any desired preheating of the primarymonochloride.

The mixed polychlorides from the bottom of the rect'fying column 45 maypass to a rectifying column 41, in which a separation may be obtained cneither side (speaking in terms of boiling-point sequence) of the desired1,3-dichloride-that is, at a temperature either above or below theboiling point of such 1,3-dichloride (about 120.4 C. in the case of1,3-dichloropropane, and about 136.0 C. in the case of1,3-dichloro-Z-methylpropane).

Conveniently, this separation is made at a lower temperature than thatboiling point, between the desired 1',3dichloride and the mixture ofother dichlorides. Such mixture of other dichlorides passes out at thetop of the rectifying column 41, to be collected in aereceptaclc 55,while a mixture of the 1,3-dichloride with any trichlorides\passes outat the bottom of the rectifying column-41. 'Ihe amount of trichloridesmay beV kept relatively small by using a large excess of material to bechlorinatedgover chlorine, so that only a small proportion ischlorinated at each pass through the reactor. Itl is of course desirablethat the dichlorides be rigorously removed from tnefmaterial to berecycled. what tgichlorides there are may be substantially separatedfrom the desired 1,3-dichloride by the rectifylng column 48, from whichthe trichlorides pass out at the bottom into a receptacle 56, while thedesired 1,3- dichloride passes out at the top into a receptacle 51.1,2,2-trichloropropane, however, is diilicultly separable vi'rom1,3-dichloropropane, because of the closeness of boiling points.

Instead of making the first separation of polychlorides, in therectiiying column 41, at a lower temperature than the boiling point ofthe 1,3-

dichloride, that krst separation may be made at a higher temperaturethan that boiling fpoint, by simply increasing the temperatures lin thatrectifying' column so that the material which passes out from the top ofthe column," is a mixture of. all the dichlorides while the liquid whichpasses out from`the bottom is a mixture of products more highlychlorinated than the dichlorides. The vlatter mixture may then beAfurther separated, as in the rectifying column 48, ii desired; or itmay be by-passedlaround the rectifying column 48 directly into thereceiver 55. The mixture of the dichlorides in this procedure goes intothe receptacle 55. The desired 1,3- dichloride may if desired beseparated from the other dichlorides, by further rectification.

For simplification of illustration, the conventional dephlegmators andwier-boxes` for separating the vapors which pass of! at 'the top of arectifying column into reux and take-oil portions are shown only inconnection with one rectifying column 23, although ordinarily they wouldbe used on all columns. g

We desirably provide dow-meters '80 in the pipes I0, and 5|, to giveinformation which facilitates the control of the quantities of reactantssupplied.

In operating our process we usually maintain` a constant supply ofhydrocarbon by the pipe |0. But that is not necessary; for thechlorination to get the 1,3-dichloride may be of the primarymonochloride alone. Such primary monochloride, obtained from any desiredsource, may be supplied by way of a pipe 6| through suitable valves toeither pipe 39 or pipe 5|, so that by opening a valve in either pipe 6|and closing the desired valves in the pipes I0 and 54, it is possible tooperate the system simply to chlorinate that primary monochloride. Inthat case the rectifying column 46 would normally be'shut oi, by closingthe valve at its entrance. If unreacted primary monochloride is to berecycled, the valve in the pipe 50 would be opened.

Ordinarily, however, as has already been stated, we prefer to provide aconstant supply of hydrocarbon, by way of the valved pipe 0; so thatthere will be `simultaneous chlorination both ci' the hydrocarbon,mainly to the monochlorides, and of the primary monochloride, mainly tothe dichlorides, in the reaction tube.

So far as the literature records, we believe, no chlorination or either'propane or isobutane to yield the 1,3-diehloride has ever previouslybeen done; and prior processes .which produce dichlorides of propaneor.isobutane have yielded only 1,2-dichlorides. If any such1,3-dichloride was ever previously produced, it was not recognized; andit was not separated as such from co-present chlorides.

In the liquid-phase chlorination of Fig. 4, an excess oi! ,the liquidhydrocarbon (propane or isobutane) to be chlorinated is pumped from ahydrocarbon-storage tank |0| by a pump |02 to a mixing pipe |03fintowhich liquid chlorine is also pumped from a chlorinestorage tank |04 bya pump |05. From the,mixingpipe |03 the liquid mixture of chlorine withan excess of hydrocarbon flows through a reactor |06, where it is heatedto cause reaction, to a cooler |01; and thence to suitable separatingapparatus such as shown while maintaining the liquid phase. If tempera.-

IMS

Vtures are desired above the critical temperature of the material to bechlorinated, as we nd advantageous, we use the hydrocarbon in a solutionof carbon tetrachloride, or other inert diluent with a ,sumciently highcritical temperature; in which case said diluent is separated from theunrecycied reaction products and recycled with the unreacted hydrocarbonand the primary monochloride.

We claim as our inventioml.. The process of producing a1,3-dichloroparamn having not to exceed 4 carbon atoms and not over '3carbon atoms in a straight chain, which consists in substituting achlorine atom for a hydrogen atom in a l-chloro-parailn having not toexceed 4 carbon atoms and not over 3 carbon atoms in a straight chain,by reacting said l-chloroparan with elemental chlorine, and separatingthe 1,3-dich1oro-paraiiin so produced from co-present chlorides. t

'2. The process of producing a 1,3-dichloroparamn having not to exceed 4carbon atoms and not over 3 carbon atoms in a straight chain, whichconsists in substituting a chlorine atom for a hydrogen atom in al-chloro-paramn having not to exceed s carbon atoms and not over 3carbon atoms in a straight chain, by reacting said 1chloroparan withelemental chlorine at a temperature between 65 C. and the criticaltemperature of the material to be chlorinated, and separating the1,3-dichloro-parailin so produced from co-present chlorides.

3. The process of producing a 1,3-dichloroparamn having not to exceed 4carbon atoms and not over 3 carbon atoms in a straight chain, whichconsists in substituting a chlorine atom for-a hydrogen atom in al-chloro-parafdn having not to exceed 4 carbon atoms and not over 3carbon atoms in a straight chain, by reacting said l-chloroparafdn withelemental ,'chlorine,

with the material to he chlorinated in liquid phase and close to itscritical temperature, and separating the 1,3-dichloro-parafdn 'soproduced from cra-present chlorides.

4i. The process ci producing a 1,3dichloroparams. having not 'to exceed4 carbon atoms and not over 3 carbon atoms in a straight chain, whichconsists in substituting a chlorine atom for a hydrogen atom in al-chloro-parafdn having not to exceed a carbon atoms and not over 3carbon atoms in a straight chain, by reacting said 1chloroparailn withelemental chlorine, with the material to be chlorinated in liquid phase,and separating the 1,3-dichlcro-para1n so produced from co-presentchlorides.

5. The process oi producing 1,3-dichioro-2- methylpropane, whichconsists in substitutiveiy chlorinating i-chloro-Z-methylpropane, andseparating the l,B-dichloro-2-methylpropane from fao-present chlorides.

6. The process of producing ldichloropropane, which consists insubstitutively cbloxinating 1-chloropropane, and separating theA.l.,3--f;lichloro propane from ccs-present chlorides.

A 7. The process of producing lndiohlorodrnethylpane, which consists insuhstitutively chlorinating 1-ch1oro-2-methylpropane at a temperaturebelow its critical temperature, and separating the1,3-dichloro-2-methylpropane irom co-prcsent chlorides.

8. The process of producing 1,3-dichloropropane, which consists insubstitutively chlorinating 1-chloropropane at a temperature below itscritical temperature, and separating the 1,3-dichloropropane fromco-present chlorides.

9. The process of producing 1,3-dich1oro-2- methylpropane, which'consists in substitutively chlorinating l-chloro-Z-methylpropane inliquid phase, and separating the 1,3-dichloro-2-fmethy1- propane fromco-present chlorides. l

10. The process of producing 1,3- dichloropropane, which consists insubstitutively'chlorinating l-chloropropane in liquid phase, andseparating the 1,3-dichloropropane from co-present chlorides.

11. The process of producing 1,3-dichloro-2- methylpropane, whichconsists in substittively chlorinating l-chloro-Z-methylpropane inliquidphase and at a temperature close', to the critical temperature,and separating the 1,3-dichloro- 2-methylpropane froml co-presentchlorides.

i2. The process of producing 1,3dichloropropane, which consists insubstitutively chlorinating l-chloropropane in liquid phase and at atemperature close to the critical temperature, and separating the1,3-dich1oropropane from copresent chlorides.

13. The process of producing a 1,3-dichloroparain having not to exceed 4carbon atoms and not over 3 carbon atoms in a straight chain, whichconsists in substituting a chlorine atom for a hydrogen atom in al-chloro-paran having not to exceed i carbon atoms and not over 3 carbonatoms in a straight chain, with the l-chloroparadin dissolved in aninert diluent of higher critical temperature, and separating the 1,3-dichloro-paramn so produced from co=present chlorides.

14. The process of producing a l.,3dichloroI parafn having not to exceedfour carbon atoms and not over three carbon atoms in a straight chain,which consists in substitutivelT chlorinat ing a paran having carbonatoms as aforesaid, at a temperature above the critical temperature ofsaid pararl but with such parailn dissolved in an inert liquid diluentof higher critical temperature, and separating the 1,3-dichloro-parainso produced from co-present chlorides.

15. The process oi producing a l,3-dichloro para'in having not to exceedd carbon atoms and not over 3 carbon atoms in a straight chain,

which consists in substituting a chlorine atom` for a hydrogen atom in al-chloro-parain hav- 4 ing not to exceed 4 carbon atoms and not over 3carbon atoms in a straight chain, with the l-chloro-paramn dissolved incarbon tetrachloride, and separating the. 1,3-dichloro-paramn soproduced from co-present chlorides.

16. The process of producing a 1,3dichloroparaiiln having not to `exceedfour carbon atoms and not over three-carbon atoms in a straight chain,which consists 'in substitutively chlorinating'a paran having carbonatoms as aforesaid, at a temperature above the critical temperature ofsaid paran but with such paraln dissolved in carbon tetrachloride, andseparating the 1,3 dichloro-parafdn so produced from co-presentchlorides.

Iv B. S. EAM T. iii/ich.

' lCERTIFLIICA'J'EfF CORRECTION.

. HENRY Bf mss,f ET AL. y

- It'ishereby certified thaty error appears in the printed specificationp of the albove numbered ypatent requiring correct'i/on u follows: Page5,5* first column, line L19, ,fr the word "treated" reed heated;land'second column, line '6,"101` "baorb" read absorb; and'that the seidLetters P'atent anouid be read with this correction therein?. that thesame may conform to the recu,

ord of the calze in the-Patent Office.

signed and sealed this 23th diy or March, A. 13.51959. Y

, Henry Van Arsdale.

7,(Seal) 'A Acting Cmmiseioneroi Patents.

